fix: Add nixpacks configuration for Astro deployment

dealplustech-astro/node_modules/unstorage/drivers/session-storage.mjs

@@ -0,0 +1,12 @@
+import { defineDriver } from "./utils/index.mjs";
+import localstorage from "./localstorage.mjs";
+const DRIVER_NAME = "session-storage";
+export default defineDriver((opts = {}) => {
+  return {
+    ...localstorage({
+      windowKey: "sessionStorage",
+      ...opts
+    }),
+    name: DRIVER_NAME
+  };
+});